1. Field of the Invention
The present invention relates to a technique for allowing a user to obtain a data item even when the data item is moved from a server to another server and the user requests the original server to provide the data item, and particularly to transfer of user authentication with respect to a server.
2. Description of the Related Art
Conventionally, the following technique is available in this field. A data management system manages files by attaching to each file a unique identifier called a “handle.” The data management system provides to a user, as a URL (Uniform Resource Locator) of a file, not a URL showing the location (combination of a located server and a path name of the file within the server) of the file, which conventionally is commonly employed, but a virtual URL designating the server name of the system and the handle of the file. When the user accesses the system using the virtual URL, the system identifies the location of the file from the handle and provides the file to the user. With this technique, even when the file is moved to an arbitrary location (directory) on the data management system, the file can be found in response to a request from a user.
This technique, however, is limited to resolving a location of a file or content managed within one data management system, and, for example, cannot handle a case in which the location of the file or the content is moved among multiple data management systems on a network.
As a method for allowing a user to obtain the file or the content by finding the location of the file or the content even when a file or a content has been moved among multiple data management servers, there may be considered a method in which a URL of the movement destination is registered in the server from which the data item has been moved and the server redirects a request to the URL of the movement destination when the user requests the movement origin server to provide the data item (HTTP redirect). This method, however, involves a problem in the user authentication of each data management server. More specifically, even when the user requests the data movement origin server to provide the data item with successful user authentication completed, when the request is redirected, in view that the user is not authenticated at the movement destination server, the request may be rejected. Even if this is not the case, the user must be authenticated again at the movement destination, which poses inconvenience to the user.
As a technique for transferring the user authentication among multiple devices, the following method is available. Specifically, a server which manages login states is provided, and the login states of users are controlled in a centralized manner. Each application transmits an inquiry to the central server when the user accesses the application, so that the login state is transferred among applications.
This related-art method requires provision of a server in order to manage the login states, and involves a problem in that the system cannot function when a problem occurs in the server.